Calculating Vorticity

ghorrocks · October 29, 2017, 01:52

Vorticity is a vector field in a 3D simulation. It does not have a single scalar value to plot on a plane as you appear to have done. You might have plotted the magnitude of the vorticity - that will not have negative values by definition and you will not see the odd symmetry which is what I think you are referring to.

Try plotting the correct vorticity component. It should show the odd symmetry.

hamed1983 · October 29, 2017, 02:43

Dear ghorrocks

Many thanks for your replying and explanation but the problem is that how I should to show the odd symmetry in CFX? I mean is it in volume rendering or any option else in CFD post?

Regards
Hamed

ghorrocks · October 29, 2017, 04:54

You have to show a vorticity component (X, Y or Z) on your plane.

hamed1983 · October 29, 2017, 05:42

Dear Ghorrocks

I have done what you advised and plotted the vorticity by component so the results are attached but I do not know whether are they really correct or not? would I please to take a look at them and guide me.

Best Regards

hamed1983 · October 29, 2017, 06:02

One thing else is these are results for logarithmic color scale and for linear color scale the results became like the attached

ghorrocks · October 29, 2017, 06:14

Doesn't the X and Z components show what you are looking for?

hamed1983 · October 29, 2017, 07:24

These are the latest results that i have achieved but I want to know are they correct?

Regards,

ghorrocks · October 29, 2017, 17:35

Good question. See FAQ: https://www.cfd-online.com/Wiki/Ansy...publishable.3F and https://www.cfd-online.com/Wiki/Ansy..._inaccurate.3F

hamed1983 · October 29, 2017, 18:02

many thanks, The results seems correct but lastly I wish to have a render for total vorticity like the attached photo I saw in another paper I have seen and I do not know how. So I appreciate if you can guide me.

regards,

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October 29, 2017, 01:52		#21
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,705 Rep Power: 143	Vorticity is a vector field in a 3D simulation. It does not have a single scalar value to plot on a plane as you appear to have done. You might have plotted the magnitude of the vorticity - that will not have negative values by definition and you will not see the odd symmetry which is what I think you are referring to. Try plotting the correct vorticity component. It should show the odd symmetry.

October 29, 2017, 02:43		#22
hamed1983 New Member Hamed Join Date: Mar 2017 Location: Iran Posts: 29 Rep Power: 9	Dear ghorrocks Many thanks for your replying and explanation but the problem is that how I should to show the odd symmetry in CFX? I mean is it in volume rendering or any option else in CFD post? Regards Hamed

October 29, 2017, 04:54		#23
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,705 Rep Power: 143	You have to show a vorticity component (X, Y or Z) on your plane.

October 29, 2017, 06:14		#26
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,705 Rep Power: 143	Doesn't the X and Z components show what you are looking for?

October 29, 2017, 17:35		#28
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,705 Rep Power: 143	Good question. See FAQ: https://www.cfd-online.com/Wiki/Ansy...publishable.3F and https://www.cfd-online.com/Wiki/Ansy..._inaccurate.3F